1. Field of the Invention
The present invention relates generally to the construction of baseball and softball bats, and more particularly, but not by way of limitation, to lighter and stronger bat constructions provided by the use of an external composite wrap on a portion of a metal bat frame.
2. Description of the Prior Art
One recent advancement in the design of high performance baseball and softball bats includes the use of an external metal shell formed about, an internal tubular bat frame as disclosed in U.S. Pat. No. 6,053,828, by Pitsenberger for xe2x80x9cSoftball Bat With Exterior Shellxe2x80x9d, assigned to the assignee of the present invention, the details of which are incorporated herein by reference.
The prior art has also included a number of other proposals for bat designs including internal and external sleeves, some of which have been constructed from composite materials.
For example, U.S. Pat. No. 5,364,095 assigned to Easton, Inc., discloses a tubular metal bat having an internal fiber composite sleeve.
U.S. Pat. No. 6,022,282 issued to Kennedy et al., discloses a ball bat having an internal metal tube surrounded by an external composite tube along its entire length (see FIG. 3).
U.S. Pat. No. 5,722,908 discloses a composite bat with a metal barrel area.
Upon review of these prior art designs, it will be seen that none of them show or suggest the use of a composite external layer along only a portion of the bat for either the strengthening of the bat at a point of maximum bending moment, or for increasing the external durability of the bat to reduce denting and the like upon impact with a ball.
The present invention provides several alternative designs for a bat including a metal frame with an exterior fiber reinforced composite shell.
In one embodiment, the bat includes a metal frame having a fiber reinforced composite outer shell formed directly about the barrel portion of the bat. Preferably, the metal frame includes a handle portion, a transition portion and a barrel portion, with the metal frame having an annular step defined therein distally of the handle portion. The fiber reinforced composite outer shell is formed about the metal frame and has a proximal end located adjacent the annular step of the metal frame.
In a second embodiment of the invention, the barrel portion of the bat includes an outer metal shell formed about the barrel portion of the frame, with a fiber reinforced composite outer shell formed about the outer metal shell.
In still a third embodiment of the invention, a fiber reinforced composite outer shell is formed around only an intermediate portion of the metal frame spanning a point of maximum bending stress, so as to provide increased stiffness of the bat at the area of the point of maximum bending stress. The metal frame of the bat extends both proximally and distally from the intermediately located fiber reinforced composite outer shell.
Methods of manufacturing bats utilizing a composite wrapped exterior shell are also disclosed.
Accordingly, it is an object of the present invention to provide improved baseball and softball bats having selected portions of a metal bat frame reinforced by an exterior fiber reinforced composite shell.
Another object of the present invention is the provision of bats having a lighter, yet stronger, construction than conventional bat designs.
Still another object of the present invention is the provision of a bat having a metal bat frame which is selectively reinforced at selected portions thereof by a fiber reinforced composite outer shell.
Still another object of the present invention is the provision of bats having improved durability and resistance to denting.
And another object of the present invention is the provision of bats having improved performance characteristics so that they will hit a ball further.
And another object of the present invention is the provision of improved methods for construction of bats having a metal frame with an exterior composite layer.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the accompanying drawings.